When she speaks with someone, Ann Romney focuses on her subject with the intensity of a mother skilled in keeping a child's attention.

That maternal presence -- and her experience with raising five sons -- has helped her connect with average voters in a way that comes less naturally for her husband, Mitt Romney.

Her challenge today at the Republican National Convention in Tampa -- her biggest stage yet -- will be to humanize her husband for Americans who haven't so far found him very likable. She needs to show that he's more than a former private equity executive good with numbers, and that he cares about their needs.

"A spouse can really personalize him," said Dianne Bystrom, director of the Carrie Chapman Catt Center for Women and Politics at Iowa State University in Ames. "She needs to talk to the American public in a personal way about what she sees in Mitt Romney, as a husband and a father." Mitt Romney's likability gap was evident in a Washington Post/ABC News poll released yesterday. The poll, taken Aug. 22-25, showed 27 percent of registered voters find Romney to be more friendly or likable among the two candidates, compared with 61 percent for the incumbent.

Ann Romney's speech probably will be the least political of any delivered at the convention and will touch on personal stories about her husband and family, according to a Romney adviser not authorized to discuss it in advance. Mitt Romney is scheduled to appear at the convention tonight, two days earlier than initially planned, according to a person who wasn't authorized to discuss the plans publicly.

Fighting Illness She's likely to talk about her 14-year battle with multiple sclerosis, a testimonial she sometimes offers on the campaign trail to assure women that her husband can be relied upon.

"Ann Romney needs to testify to that," Matthew Dowd, a Bloomberg analyst and political consultant told those gathered at a Bloomberg-sponsored panel discussion in Tampa yesterday.

She was also diagnosed with breast cancer in January 2009, about a year after her husband's first White House bid. She rarely talks about the disease in public, although she has said in interviews that she had surgery and radiation after it was caught early.

Because of her multiple sclerosis, Ann Romney doesn't have the campaign trail stamina of first lady Michelle Obama. In March, she had a flare-up of the autoimmune disease that affects the central nervous system.

Ann Romney called the incident a "real scare" and said it was the result of the stress and strain of the campaign.

Keeping Pace "It was just a reminder that I can't keep up the pace," she told NBC's "Rock Center" program. She didn't tell anyone at the time, she said, because she didn't want to worry her husband.

When she travels with her husband, she sometimes plays a maternal role on the campaign plane, offering cookies to reporters or asking whether they are getting enough sleep.

This week, Ann Romney has practiced her presentation with the guidance of Stuart Stevens. The involvement of the campaign's top strategist shows the importance of her address.

"She's going to do terrific," her husband predicted to reporters before arriving at one of the sessions.

Besides trying to help Mitt Romney connect with all voters, Ann Romney, 63, will have a second, critical audience.

Gender Gap Women, who represent 52 percent of the U.S. electorate, are a crucial group in every presidential election and polling shows President Barack Obama with a significant advantage among female voters. They prefer Obama over Romney by an eight-percentage- point margin, according to Gallup daily tracking polls conducted July 30 through Aug. 19.

The existence of Romney's gender gap has received renewed focus in recent days after Todd Akin, a Republican candidate for U.S. Senate from Missouri, said Aug. 19 that "legitimate rape" rarely leads to pregnancy and so abortion shouldn't be allowed in rape cases. Democrats have worked to keep the controversy alive and have continued to criticize Republicans as being hostile toward women.

No matter how well Ann Romney does in her speech, Bystrom said she suspects it will do little to narrow the gender gap.

"The gap is more issue-based," she said, noting the different policy views on abortion rights, environmental matters and education held by Romney and Obama.

Struggling Women In April, she was dragged into a campaign controversy when Democratic strategist Hilary Rosen said in an interview on CNN that Ann Romney, who grew up wealthy and hasn't had a career outside the home, couldn't relate to working women struggling in the economic downturn.

Ann Romney fired back at Rosen's comments, saying raising five sons was a full-time job that her husband considered as important as running a private-equity firm.

"I made a choice to stay home and raise five boys," she wrote on her Twitter account. "Believe me, it was hard work." Ann Romney's horse dressage hobby, including the appearance of her mare, Rafalca, in this summer's Olympic Games in London, opened the family to more criticism that it lives a privileged existence. Her husband had added to that notion in February when he said his wife drives "a couple of Cadillacs.' Unlike Michelle Obama, who generated controversy during the campaign four years ago for saying that for the first time in her adult life she was ''really proud of my country,'' Ann Romney has so far avoided any missteps.

'Good Communicators' A USA Today/Gallup Poll released yesterday shows 42 percent of Americans have a favorable impression of Ann Romney, which is on par with other presidential contenders' wives about to make their first convention appearances. That's below Michelle Obama, who was viewed favorably by 64 percent of adults in an AP-GfK poll conducted Aug. 16-20.

''Michelle Obama and Ann Romney are more equally matched on the campaign trail than we have had in a long time," Bystrom said. "They are both good communicators for their husbands." Not to be outdone, Obama's re-election campaign has Michelle Obama scheduled to make a high-profile appearance tomorrow night on "The Late Show with David Letterman."